A pool containing nuclear fuel is different from a pool containing a running nuclear reactor with no other shielding, though.

A "pile" is not just a description of the thing, it is an actual formal term (old one!) meaning "reactor". So not just a bunch of radioactive matetial.

Here it is in written form. The punchline is worth the read/watch.

https://what-if.xkcd.com/29/

What skill do you develop to avoid the need for a helmet? Is it like a spidey sense, or do you hit yourself in the head so frequently your skull thickens enough to protect your brain from falling objects?

It tends to be the opposite. Kids are usually fine, if they cross a construction site once, they would be really unlucky to have something fall on their head, even if they are careless. Professionals who work on site for thousands of hours will have something fall on their head eventually, even if they are careful. That's just probabilities. Take 10 times the risks for 1/10000th of the time and you are still 1000 times less likely to get injured.

OSHA 30 hour here: no the f** it isn't. You only lose an eye once before it's just gone. Hearing can only get worse. Some stuff will just kill you, some more slowly than others. Only literal children can bounce back from a what would otherwise be a fatal injury, but that's a very narrow slice of how you can get hurt.

> It's entirely possible to build up skills allowing you to avoid using PPE

Yes, but you only need to mess up once and your skill doesn't save you from other people mistakes.

No, it's not.

Humans don't have perfectly consistent attention, and by the time you think you have any skill like that your attention is even less consistent than before you started "practicing".

No it isn’t. Over an 80,000 hour career in construction/other dangerous field, you will eventually have an incident that will make you thankful for PPE.